sum = 0
for i = 1, 100 do
    sum = sum + i
end
print("1到100的和: ", sum)

sum = 0
for i = 1, 100, 2 do
    sum = sum + i
end
print("1到100的奇数的和: ", sum)

sum = 0
for i = 100, 1, -2 do
    sum = sum + i
end
print("100到1的偶数的和: ", sum)

